Sound unit and film drive therefor



Sept. 7, 1937. E. Ross ET AL SOUND UNIT AND FILM DRIVE THEREFOR FiledJuly 10, 1935 FIG. 1

FIE' E FIE- FIG 5 INVENTDRS Ernest Russ Harald J. Hashruuck, Jr.

BY MM ATTORNEY Patented Sept. 7, 1937 UNITED STATES PATENT OFFICE ErnestRoss, Elmhurst, Long Island, and Harold J. Hasbrouck, Jr., Flushing, N.Y., assignors to United Research Corporation,

Long Island City, N. Y., a corporation of Delaware Application July 10,1935, Serial No. 30,742

9 Claims.

This invention relates to talking motion picture apparatus andparticularly to that portion of the sound unit which continuously drivesthe film at the proper speed and maintains the film at the properposition with respect to a beam of light.

One of the essentials for perfect sound recording or reproduction isthat the film be driven at a constant uniform speed at at least onepoint, and

that the sound track portion of the film be maintained in the properspatial relationship at this point. In recording, a constant intensitylight beam is modulated either in intensity or position beforeimpression upon the light sensitive emulsion of a film. In reproduction,a constant intensity light beam is modulated by a sound track on a filmand projected therethrough onto a light sensitive device. In both casesit is desirable that there be no film weave or variations in speed atthe point where the film and light beam contact,

known in the art as the translation point.

The present invention contemplates maintaining the film at a contantspeed at the translation point by the use of inertia in the form of aflywheel, and guiding the film adjacent the translation point bymechanism which utilizes friction to introduce a transverse directionalcomponent to the film. The basic principle of this invention isdisclosed in co-pending application Serial No. 28,648, filed June 27,1935, and the method and certain specific apparatus are claimed therein.The present application discloses a novel mounting for a film guidingroller and flywheel.

The object of the invention, therefore, is to facilitate guiding anddriving a linear record carrier in the form of a talking motion picturefilm past a translation point.

Another object of the invention is to facilitate adjustment of the filmguiding'means.

Other objects and specific features of the invention will be realizedand the invention more fully understood by reference to the followingdescription read in conjunction with the accompanying drawing, in which45 Fig. l is an elevational view of the film driving portion of a soundunit.

Fig. 2 is a side elevational view of the apparatus of Fig. 1.

Fig. 3 is a cross-sectional view of the moimting of the roller andflywheel adjusting mechanism; and

Figs. 4 and 5 are cross-sectional views of a detail of the adjustingmechanism.

Referring to the drawing, a casing 4 houses in a compartment 6 thereof adrive sprocket 'l with its pad rollers 9 and II]. There is also includedin compartment 6 an idler roller l2, a guide roller 3, with its guidingpad roller l5, a film gate shoe IT, a flywheel roller |8 with its springpressed roller 2|, a guide roller 22, a film stiffening shoe 24, and aguide roller 23. This apparatus drives and guides a film 25 through thesound unit, as illustrated in the drawing, the film, of course, beingsupplied from supply and take-up reels, not shown.

The invention is disclosed embodied in a sound recording unit in whichmodulated light is impressed upon the film at a translation point 21through an optical system, not shown, as the film is maintained againstthe shoe IT by any suitable gate. The flywheel roller l8 has a flange 28thereon against which the film is maintained by tilting a common shaft30 of the roller l8 and the flywheel 9, as will be described later. Thefilm is also guided prior to reaching the translation point by the padroller I5 having a spring flange 32 thereon which urges the film againstopposing flange 33 (see Fig. 2), such a pad roller being disclosed andclaimed in co-pending application Serial No. 25,423 filed June '7, 1935.

Referring now to Fig. 3, the roller l8 and fiywheel I9 have their shaft30 mounted on roller bearings 34 and 35, the bearings being fixed in aspecially formed bracket 36 which projects through a mounting plate 5but does not make contact therewith. A ring of felt 31 fills the gapbetween the bracket 36 and the plate 5.

The

bearing portion of the bracket 36 has a cylindrical surface 38 formed ina slot 39, as shown in Fig. 1. This slotted arrangement maintains thesurface 38 in position on a mounting or supporting bracket 4| attachedto the plate 5 by screws 42. A bolt 43 is fixed to the bearing bracket36 and extends through an oversized stepped opening 45 in the supportingbracket 4|, the lower portion 46 of the opening being elongated as shownin Figs. 4 and 5. Movement of the bolt 43 in the plane of the paper,therefore, will tilt the shaft 30 in the plane of the paper or in avertical plane. The bracket 36, however, is prevented from moving in anyother direction by the slot 39.

Referring now to Figs. 4 and 5, together with Fig. 3, a cylindricalbushing 41 with an enlarged hexagonal top is fitted in the large portion46 of the opening 45 and accommodates the bolt 43 in an eccentric holetherein. A washer 48 having a slot 49 slidable on a. pin on bracket 4|surrounds the bushing 41, this washer having the same curvature as thatof the lower surface of bracket 4| which has a radius R1 with a centercorresponding to the median line of the film. The upper surface ofbracket 4| or lower surface of bracket 35 has a curvature with radius R2with the same center 0. The axis of the shaft 38 is in effect pivoted atpoint 0. A coil spring 50 abuts the eccentric drilled bushing (if andthe shoulder formed by the steps of the opening 45. The bushing 47 ismaintained against the tension of the spring 50 and in fixed positionwith respect to the bracket 45 by a locknut 5| threaded on the end ofbolt 4-3.

To adjust the angle of the shaft 3i! in the plane.

of the paper, which is also the plane of the film at the point ofcontact betweenthe roller i8 and its spring pressed roller 2|, it isonly necessary. to loosen the nut 5| and turn the bushing ll with awrench to the desired degree. The nut 5| is then tightened. What causesthe angular adjustment is the eccentricity of the opening in the bushing41 into which the bolt 43 is fitted. Fig. 4 showsone extreme position ofadjustment, the center line 53 representing the axis of the shaft 30.Fig. 5 shows the position of the bushing 4'! in its horizontal orneutral position in 35 which case the thicker portion of the bushingfills the lower part of the elongated opening .5. By making the opening65 elongated, no angular displacement of the bolt 53 in a planeperpendicular to the shaft 3!] is obtained, the only direction 30 ofmovement of the bolt 43 being in the desired plane.

In this type of film driving and guiding, the film is maintained againstthe surface of the roller l8 by the spring pressed roller 2| underaction 35 of a tension spring 55 operating upon a pivoted lever 55having a notch 5'5 therein for holding the roller 2| in film threadingposition. The roller 2| is mounted upon a yoke 59, the shaft of theroller 2| being fitted in a notch in the end 40 thereof and held in thenotch by a fiat lever spring 60. A hand knob 6| facilitates opening andclosing the roller. roller arrangement, a uniform pressure is maintainedon the film as it contacts the surface of 45 roller l8. Roller l8, asmentioned above, is rotated by the pull of the film andmaintains auniform speed of rotation by the inertia of the flywheel I9. The drag onthe film caused by the abaxial relationship between the shaft of theroll- 50 er i8 and the shaft of the roller 2|, as disclosed in copendingapplication Serial No. 28,648, filed June 27, 1935, mentioned above,urges the film toward the flange 28 and maintains it at a fixedposition. with respect to the translation point 27. 55 Before reachingthe translation point, the film is also positioned by the spring flangeof the pad roller l5.

Although the present device isa sound recorder wherein raw film is lightimpressed with sound 60 modulated light, it may also be used forreproducing, or the recording may be monitored by the use of aphoto-sensitive device, such as a selenium cell 53, disclosed andclaimed in copending application Serial No. 16,578 filed April 65 16,1935. For sound monitoring, the light impressed upon the film passesthrough an opening inthe shoe andimpinges upon the light sensitivesurface of the selenium cell 63. The cell 63 is held in position byelectrical contact springs 70 64 which are mounted on the plate 5,insulated therefrom, and terminated in electrical terminals 66. Theseterminals may be connected to an amplifier andthe recording monitored bythe light which emerges from the film. For repro- 75 ducing, theapparatus functions in the same With this spring pressed.

drical base, a second supporting bracket having a cylindrical surfacefor accommodating the base of said first bracket, a bolt fixed to saidfirst bracket and passing through an opening in said second bracket; andan eccentric bushing surrounding said bolt and positioned in the openingof said second bracket, the angular position of said bushing determiningthe position of the axis of rotation of said roller and flywheel.

2. A film drive comprising a roller having a flywheel integraltherewith, a second roller producing a predetermined pressure on saidflywheel roller, means for advancing a film between said rollers, saidrollers and flywheel being rotated by said film, a support for saidflywheel and roller having a cylindrical base, a fixed support foraccommodating said base and having an opening therein, and meansattached to said support and passing throughsaid opening for varying theposition of the axis of rotation of said flywheel roller with respect tothe direction of movement of said film.

3. A sound unit comprising means for advancing film therethrough, aplurality of guide rollers for determining the direction of travel ofsaid film, means for positioning the surface of said film with respectto a light beam, a roller having a flywheel integral therewith forstabilizing the speed of advancement of said film at thepoint of contactbetween said light beam and said film, a second roller maintaining apredetermined pressure of said film against said flywheel roller, saidrollers being rotated by the pull of said film, a

mounting for said flywheel roller and flywheel, said mounting having acurved base, a support for said mounting having a curved top cooperatingwith said curved base, means inter-connecting said support and mountingfor adjusting their relativepositions along the curve of said base, andmeans for positioning the edge of said film at said contact point, saidmeans being located immediately before and after said contact point.

4. An adjustable mounting for a film-pulled roller and flywheelcomprising a shaft having said roller and flywheel mounted thereon, abearing support for said shaft having a cylindrical surface whose radiusof curvature has a center corresponding to the median line of said filmon said roller, a fixedbracket for accommodating said cylindricalsurface and having an opposite curved surface whose radius of curvaturecoincides with that of said first radius, said bracket having an openingtherein, means fixed to said shaft bracket and positioned in saidopening, and means for adjusting the position of said last mentionedmeans to control the axis of rotation of said roller and flywheel shaft.

5. Means for adjusting an axis of rotation of a shaft in the plane ofsaid axis :comprising a bracket for supporting said shaft having acurved base whose radius of curvature has a center on said axis, a fixedsupporting bracket having an elongated opening therein and a surfacewith the same curvature as said first bracket, said brackets beingadapted to move relatively to one another on said surfaces solely in onedirection, means attached to said first bracket and passing through saidopening, said means being adapted to adjust said axis in a definiteplane including said axis, and a cylindrical bushing positioned in saidelongated opening and having an eccentric hole therein to accommodatesaid last mentioned means, the angular position of said bushingdetermining the position of said axis in said definite plane.

6. An adjustable mounting for a film pulled roller and flywheelcomprising a shaft having said flywheel and roller mounted thereon, abracket having a cylindrical surface of a definite curvature, a fixedbracket for accommodating said curvature and having an opening therein,a bolt attached to said first bracket and positioned in said opening,said opening being elongated in a plane perpendicular to the plane ofsaid axis, a bushing positioned in said elongated opening andaccommodating said bolt in an eccentric hole in said bushing, angulardisplacement of said bushing determining the position of said bolt inproportion to the eccentricity of said bushing, and means formaintaining said bolt in fixed position on said support.

7. A film drive comprising a roller, a second roller associated withsaid first roller, means for advancing a film between said rollers, saidrollers being rotated by said film, a mounting for said first mentionedroller, said mounting having a curved base, a fixed support for saidmounting,

said support having a curved top co-operating with the curved base ofsaid mounting, and means connecting said mounting and said support foradjusting the relative positions therebetween, said adjustment varyingthe position of the axis of said first roller with respect to saidsecond roller.

8. A film drive in accordance with claim 7 in which means are providedfor positioning the surface of said film prior to its reaching saidrollers and means are provided for positioning the edge of said filmprior to its reaching said surface positioning means.

9. A film drive system comprising a roller adapted to be rotated by filmpassing thereover, a second roller co-operating with said first rollerfor maintaining contact of said film with said roller at a predeterminedpressure, bearings for said first roller, a mounting for said bearings,said mounting having a base with a cylindrical curvature, a fixedsupport for supporting said mounting, the top of said supportaccommodating the cylindrical curvature of the base of said mounting,and means fixedly attached to said mounting and passing through saidsupport for rotating said mounting with respect to said support, saidmounting varying the position of the axis of the bearings of said firstmentioned roller with respect to the axis of the bearings of said secondmentioned roller.

ERNEST ROSS. HAROLD J. HASBROUCK, JR.

